Short-range optical amplification module, spectacles, helmet and VR system

ABSTRACT

A short-range optical amplification module, spectacles, a helmet and a VR system. The amplification module includes a reflective polarizing plate, a first phase delay plate, a second lens and a second phase delay plate, and a first lens. In the second lens, the optical surface adjacent to the second phase delay plate is a transflective optical surface. The first focal length f2 of the second lens meets the condition: 1F≤f2≤2F, wherein F is the system focal length of the optical amplification module. By performing parameter refining on the first focal length f2 that influences the optical amplification effect, the module can keep a small overall thickness while obtaining a large optical amplification effect, and the VR device can realize a good field angle, a large oculomotor range and a high-quality imaging effect.

FIELD

The present invention relates to an optical apparatus, and inparticular, to a short-range optical amplification module, spectacles, ahelmet and a Virtual Reality (VR) system.

BACKGROUND

In the structure of an existing optical amplification module, as shownin FIG. 1, it includes a reflective polarizing plate 01, a first phasedelay plate 02, a lens unit 03 and a second phase delay plate 04 thatare arranged sequentially. In the lens unit 03, the optical surfaceadjacent to the second phase delay plate 04 is a transflective opticalsurface. In use, an optical image is transmissively amplified by thelens unit 03, then reflected by the reflective polarizing plate 01, andagain amplified by the lens unit 03, and finally enters the human eyevia the reflective polarizing plate 01. Moreover, other lens units thatdo not influence the phase delay of light are further set on either sideof any one of the reflective polarizing plate 01, the first phase delayplate 02, the second lens 03 and the second phase delay plate 04. Thelens unit 03 and other lens units constitute a lens assembly, which isthe core part that influences the amplification effect on the opticalimage.

In order to provide a good user experience, an intelligent VirtualReality (VR) wearable device needs to provide a wide field angle, alarge eyebox, high-quality imaging effect and a compact ultrathinstructure, etc. In order to achieve the above objects, the lens assemblyin the structure of the optical amplification module needs to beoptimized. However, the structure of the existing optical amplificationmodule does not have an optimized design, thus it cannot be guaranteedthat the above objects can be achieved in the whole range, that is, itcannot guarantee a good user experience.

SUMMARY

The embodiments disclosed herein provide a short-range opticalamplification module, spectacles, a helmet and a VR system, therebysolving the problem of the prior art.

On the first aspect, there is provided a short-range opticalamplification module, which includes a reflective polarizing plate, afirst phase delay plate, a second lens and a second phase delay platethat are arranged sequentially, wherein:

A first lens is further set on either side of any one of the reflectivepolarizing plate, the first phase delay plate, the second lens and thesecond phase delay plate;

In the second lens, the optical surface adjacent to the second phasedelay plate is a transflective optical surface;

The first focal length f2 of the second lens meets the followingcondition: 1F≤f2≤2F, wherein, F is the system focal length of theshort-range optical amplification module.

In conjunction with the first aspect, in a first possible implementationmode of the first aspect, the effective focal length fs4 of thereflection surface of the transflective optical surface meets thefollowing condition: 1.5F≤fs4≤5F.

In conjunction with a second possible implementation mode of the firstaspect, in the second possible implementation mode of the first aspect,the effective focal length fs4 of the reflection surface of thetransflective optical surface meets the following condition: 1F≤fs4≤2F.

In conjunction with the first aspect, in a third possible implementationmode of the first aspect, the first focal length f2 of the second lensmeets the following condition: 1.5F≤f2≤2F.

In conjunction with the third possible implementation mode of the firstaspect, in a fourth possible implementation mode of the first aspect,the first focal length f2 of the second lens is 1.6F.

In conjunction with the first aspect or in the first possibleimplementation mode of the first aspect to the fourth possibleimplementation mode of the first aspect, in the second lens, the focallength fs3 of the optical surface adjacent to the first lens meets thefollowing condition: |fs3|≥2F.

In conjunction with the first aspect or in the first possibleimplementation mode of the first aspect to the fourth possibleimplementation mode of the first aspect, the focal length f1 of thefirst lens meets the following condition: |f1|≥3F.

In conjunction with the first aspect or in the first possibleimplementation mode of the first aspect to the fourth possibleimplementation mode of the first aspect, the thickness of theshort-range optical amplification module is 11˜28 mm.

In conjunction with the first aspect or in the first possibleimplementation mode of the first aspect to the fourth possibleimplementation mode of the first aspect, the eye relief of theshort-range optical amplification module is 5˜10 mm.

In conjunction with the first aspect or in the first possibleimplementation mode of the first aspect to the fourth possibleimplementation mode of the first aspect, the aperture D, through whichthe light L that takes part in imaging via the second lens and the firstlens passes, meets the following condition: 0.28F≤D≤0.45F.

In the second aspect, there is provided short-range opticalamplification spectacles, which include the short-range opticalamplification module of the first aspect, and the short-range opticalamplification spectacles further include a display screen, which is setcoaxially or noncoaxially with the short-range optical amplificationmodule.

In the third aspect, there is provided a short-range opticalamplification helmet, which includes the short-range opticalamplification module of the first aspect, and the short-range opticalamplification helmet further includes a display screen which is setcoaxially or noncoaxially with the short-range optical amplificationmodule.

In the fourth aspect, there is provided a short-range opticalamplification VR system, which includes the spectacles of the secondaspect or the helmet of the third aspect.

In the embodiments disclosed, parameter refining on the first focallength f2 that influences the optical amplification effect enables themodule to keep a small overall thickness while obtaining a large opticalamplification effect, so that the VR device can achieve a wide fieldangle, a large eyebox, high-quality imaging effect, and hence a betteruser experience.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features will become clear from thefollowing description taken in conjunction with the preferredembodiments with reference to the accompanying drawings, in which:

FIG. 1 is a diagram schematically showing the overall construction of ashort-range optical amplification module of the prior art;

FIG. 2 is a diagram schematically showing the overall construction of ashort-range optical amplification module according to Embodiment 1;

FIG. 3 is an MTF diagram of a short-range optical amplification moduleaccording to Embodiment 1;

FIG. 4 is a distortion diagram of a short-range optical amplificationmodule according to Embodiment 1;

FIG. 5 is a field curvature diagram of a short-range opticalamplification module according to Embodiment 1;

FIG. 6 is a diagram schematically showing the overall construction of ashort-range optical amplification module according to Embodiment 2;

FIG. 7 is an MTF diagram a short-range optical amplification moduleaccording to Embodiment 2;

FIG. 8 is a distortion diagram of a short-range optical amplificationmodule according to Embodiment 2;

FIG. 9 is a field curvature diagram of a short-range opticalamplification module according to Embodiment 2;

FIG. 10 is a diagram schematically showing the overall construction of ashort-range optical amplification module according to Embodiment 3;

FIG. 11 is an MTF diagram of a short-range optical amplification moduleaccording to Embodiment 3;

FIG. 12 is a distortion diagram of a short-range optical amplificationmodule according to Embodiment 3;

FIG. 13 is a field curvature diagram of a short-range opticalamplification module according to Embodiment 3;

FIG. 14 is a diagram schematically showing the overall construction of ashort-range optical amplification module according to Embodiment 4;

FIG. 15 is an MTF diagram of a short-range optical amplification moduleaccording to Embodiment 4;

FIG. 16 is a distortion diagram of a short-range optical amplificationmodule according to Embodiment 4;

FIG. 17 is a field curvature diagram of a short-range opticalamplification module according to Embodiment 4.

FIG. 18 is a diagram schematically showing the overall construction of ashort-range optical amplification module according to Embodiment 5;

FIG. 19 is an MTF diagram of a short-range optical amplification moduleaccording to Embodiment 5;

FIG. 20 is a distortion diagram of a short-range optical amplificationmodule according to Embodiment 5; and

FIG. 21 is a field curvature diagram of a short-range opticalamplification module according to Embodiment 5.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to make one skilled in the art better understand the solutionsof the present invention, the embodiments will be described clearly andfully below with reference to the accompanying drawings. It is obviousthat from the teaching of this invention the skilled person may findother embodiments to realize the teaching of the present inventionwithout applying additional inventive activity. These embodiments arestill under the scope of the present invention.

Referring to FIGS. 2, 6, 10, 14 and 18, they are structural diagrams ofthe short-range optical amplification modules according to theembodiments. The short-range optical amplification module includes areflective polarizing plate, a first phase delay plate, a second lens 20and a second phase delay plate that are arranged sequentially, wherein,a first lens 10 is further set on either side of any one of thereflective polarizing plate, the first phase delay plate, the secondlens 20 and the second phase delay plate. Because the reflectivepolarizing plate, the first phase delay plate and the second phase delayplate are not shown in FIGS. 2, 6, 10, 14 and 18, reference may be madeto FIG. 1 for examples of these features. It should be noted that, inthe drawings of these embodiments, the first lens 10 is set on the leftof the second lens 20; however, in practical application, the first lens10 may also be set on the right of the second lens 20, which will not bedescribed again.

The first lens 10 and the second lens 20 are the core parts thatinfluence the optical amplification effect of the short-range opticalamplification module whose system focal length F is 15˜35 mm, however,the system focal length F is not limited to this numerical range, forexample, it may also be 8˜30 mm; furthermore, the first lens 10 and thesecond lens 20 may be attached to each other, or a certain space mayexist therebetween.

As defined in these embodiments: the optical surface on the left side ofthe first lens 10 is a first optical surface E1, and the optical surfaceon the right side of the first lens is a second optical surface E2; theoptical surface on the left side of the second lens 20 is a thirdoptical surface E3, and the optical surface on the right side of thesecond lens 20 is a fourth optical surface E4.

After passing successively through the second phase delay plate, thesecond lens 20, the first lens 10 and the first phase delay plate, anoptical image from the object side arrives at the reflective polarizingplate, where it is reflected for the first time, then after passingthrough the first phase delay plate, it arrives at the fourth opticalsurface E4, where it is reflected for the second time, and then itreaches the human eye after passing through the first phase delay plateand the reflective polarizing plate. Thus, the optical image may bereflected and amplified twice in the short-range optical amplificationmodule, thereby meeting the requirement of optical amplification.

Furthermore, in these embodiments, a first lens 10 and a second lens 20are provided, wherein the two lenses work together to contribute to thesystem focal length, balance the aberration for each other and improvethe imaging quality.

In order to realize a wide field angle, a large eyebox, high-qualityimaging effect and a compact ultrathin structure when the short-rangeoptical amplification module is applied to an intelligent VR wearabledevice, the first focal length f2 of the second lens 20 should meet thefollowing condition:F≤f2≤2F  (1)

Wherein, the focal length measured after the incident light penetratesthrough the third optical surface E3 and is reflected by the fourthoptical surface E4 is defined as the first focal length f2.

The first focal length f2 of the second lens 20 is the main source ofthe system optical power. If the reflection surface-containing opticalpower is too high, for example, approaching the overall optical power ofthe system (f2<F), it will be too difficult to correct the aberration.If the reflection surface-containing optical power is too low (f2>2F),the optical power burdened on other lenses will be too high, and lensesneed to be added to correct the aberration, which is adverse to thecompact and lightweight design of the optical system.

Condition (1) defines the specific range of the first focal length f2 ofthe second lens 20. A screen with a size of 1.3˜2.6 inch is used in theoptical system, thus a wide field angle may be obtained, and it mayallow a high screen resolution, wherein the field angle V that may beobtained is 90°˜100°, and the screen resolution that may be allowed is800*800˜4000*4000.

In the second lens 20, the effective focal length fs4 of the reflectionsurface of the fourth optical surface E4 meets the following condition:1.5F≤fs4≤5F  (2)

In these embodiments, the focal length measured after the incident lightis reflected by the fourth optical surface E4 is defined as theeffective focal length fs4 of the reflection surface.

The reflection surface of the fourth optical surface E4 is the mainsource of the system optical power. If its optical power is too high,for example, approaching the overall optical power of the system(fS4<F), it will be too difficult to correct the aberration.Furthermore, the optical surface may appear too curved and the lens toothick, thereby causing the increase of the thickness of the system,which is adverse to the lightweight and ultrathin design of a VRwearable device requires. On the contrary, if its optical power is toolow (fs4>5F), the optical power burdened on other lenses will be toohigh, and additional lenses need to be added to correct the aberration,which is adverse to the compact and lightweight design of the opticalsystem.

In the second lens 20, the focal length fs3 of the third optical surfaceE3 meets the following condition:|fs3|≥2F  (3)

If the focal length fs3 is too short, it means that the second lens 20may be too curved, which is adverse to the correction of aberration.Furthermore, if the second lens 20 is too curved, it may increase thethickness of the optical system, which is adverse to the lightweight andthin design that a VR wearable device requires.

The focal length f1 of the first lens 10 meets the following condition:|f1|≥3F  (4)

If the focal length f1 is too short (|f1|<3F), it means that the firstlens 10 will be too curved, and stronger aberration may be introducedinto the whole optical system. Furthermore, the thickness of the firstlens 10 will also be increased, which is adverse to the light and thindesign that a VR wearable device requires.

In order to achieve a small and ultrathin VR wearable device, thethickness of the short-range optical amplification module is designed as11˜28 mm, wherein the thickness is the maximum distance between the twosides of the short-range optical amplification module along its opticalaxis direction.

In consideration of both the comfortability and imaging quality of theVR device, the eye relief of the short-range optical amplificationmodule is designed as 5˜10 mm, wherein the eye relief is the distancebetween the eyeball and the eyepiece (the optical surface nearest tohuman eye) at which an observer can see clearly the image within thefield of view.

In order to obtain both a large eyebox and good imaging quality, theadjustable range of the aperture is designed as 2.2F˜3.5F. That is, theaperture D, through which the light that takes part in imaging via thesecond lens and the first lens passes, meets the following condition:0.28F≤D≤0.45F  (5)

Corresponding to condition (5), the eyebox A obtained is 5˜10 mm.

Moreover, the numerical range of the conditions (1) and (2) may bebetter set as follows:1.5F≤f2≤2F  (1a)1F≤fs4≤2F  (2a)

The short-range optical amplification module according to theseembodiments will be further described below in conjunction with thetables attached.

In the specific design parameter table of the short-range opticalamplification module of each embodiment, OBJ represents an object in theoptical system, IMA represents an image in the optical system, STOrepresents an diaphragm in the optical system, Thickness represents thedistance between optical surface i and optical surface i+1, wherein irepresents the sequence (i₀)+1 of optical surfaces starting from theobject side. The light goes from the first lens 10 on the left side tothe second lens 20 on the right side, and when it meets a material(Glass) listed as MIRROR, it will be reflected towards the reversedirection, and when it meets a second MIRROR, it will be reflected againfrom left to right, and finally it will reach the image surface.

Embodiment 1

As shown in FIG. 2, in the short-range optical amplification module, thefirst focal length f2 of the second lens 20 is designed as equal to thesystem focal length F, wherein:

The specific design parameters of the short-range optical amplificationmodule are as shown in Table 1:

Surf Type Radius Thickness Glass Diameter Conic OBJ STANDARD Infinity−200 400 0 STO STANDARD Infinity 9 7 0 2 STANDARD Infinity 0.2 PMMA24.685 0 3 STANDARD Infinity 2 H-ZF52A 24.89819 0 4 STANDARD 8889.210156 26.6281 −33 5 STANDARD −55 2 H-QK1 38.26443 0 6 STANDARD −56 −2MIRROR 40.54977 0.915605 7 STANDARD −55 −9.210156 40.02718 0 8 STANDARD888 −2 H-ZF53A 39.72057 −33 9 STANDARD Infinity −0.2 PMMA 39.69469 0 10STANDARD Infinity 0 MIRROR 39.69181 0 11 STANDARD Infinity 0.2 PMMA39.69181 0 12 STANDARD Infinity 2 H-ZF52A 39.68893 0 13 STANDARD 8889.210156 39.66306 −33 14 STANDARD −55 2 H-QK1 39.77483 0 15 STANDARD −561 40.25757 0.915605 16 STANDARD Infinity 0.4 BK7 41.00791 0 IMA STANDARDInfinity 41.12973 0

In Table 1, the first row OBJ represents the design parameters relatedwith the object plane; the second row STO represents a diaphragm in theoptical system, the aperture of which is 7 mm; the third row representsa membrane consisting of a reflective polarizing plate and a first phasedelay plate in the optical module, of which the type is STANDARD(standard plane), the material is PMMA, the diameter is 24.685 mm, andthe aspheric coefficient is 0; the fourth row and the fifth rowrespectively represent the data corresponding to the first opticalsurface E1 and the second optical surface E2 of the first lens 10, thecurvature radius of the first optical surface E1 is infinite, thecurvature radius of the second optical surface E2 is 888 mm, thethickness of the first lens 10 is 2 mm (that is, the distance betweenthe first optical surface E1 and the second optical surface E2, and thethickness value in the fourth row), and the material is H-ZF52A; thesixth row and the seventh row respectively represent the datacorresponding to the third optical surface E3 and the fourth opticalsurface E4 of the second lens 20, the curvature radius of the thirdoptical surface E3 is −55 mm, the curvature radius of the fourth opticalsurface E4 is −56 mm, the thickness of the second lens 20 is 2 mm (thatis, the distance between the third optical surface E3 and the fourthoptical surface E4, and the thickness value in the sixth row), and thematerial is H-QK1; the eighth row to the sixteenth row represent therelevant parameters in the reflection and transmission of light amongthe membrane, the first lens 10 and the second lens 20, which may not bedescribed again one by one here; the seventeenth row represents theglass membrane in the liquid crystal layer of the display screen, ofwhich the thickness is 0.4 mm, and the material is BK7; the eighteenthrow IMA represents the final imaging of the light.

Other corresponding parameters of the short-range optical amplificationmodule are as shown in Table 2:

Screen size C (inch) 2.22 Field angle V (°) 90 System focal length F(mm) 29.16 The effective focal length fs4 of the 1F reflection surfaceof the transflective surface Eyebox (mm) 7 Screen resolution 800 * 800Optical system thickness (mm) 23.8 Eye relief (mm) 9 F# aperture 4Optical outer diameter (mm) 40 System distortion D 29.2 First focallength f2 of the second lens 1F Focal length f1 of the first lens−35.4F   

By setting the relevant parameters as shown in Table 1, it is clear fromTable 2 that the focal length of the first lens 10 will be −35.4F(−1032.26 mm), the first focal length f2 of the second lens 20 is F(29.16 mm), and the effective focal length of the reflection surface ofthe transflective surface of the second lens 20 is F (29.16 mm), and thethickness of the optical system is designed as 23.8 mm, thus it mayobtain a system focal length of 29.16 mm and a field angle of 90°; bydesigning the aperture set in front of the short-range opticalamplification module as 4, that is, designing the diameter D of thecorresponding diaphragm as 7.29 mm, a large eyebox of 7 mm may beobtained accordingly.

Furthermore, the screen size is designed as 2.22 inch, and the eyerelief is designed as 9 mm; in conjunction with the MTF diagram of FIG.3, it may obtain the abscissa (spatial frequency per millimeter) valuewith an average ordinate (modulation transfer function) higher than 0.18in each visual field, thereby it may be obtained that the resolvingpower of the short-range optical amplification module may support aresolution of 800*800.

Moreover, it may be obtained from FIG. 4 that, in this embodiment, theoptical imaging distortion factor is controlled within a range of(−29.2%, 0), and the field curvature in FIG. 5 is controlled within therange of (−10 mm, 10 mm).

Embodiment 2

As shown in FIG. 6, in the short-range optical amplification module, thefocal length of the first lens 10 is designed as 10.4F, and the firstfocal length f2 of the second lens 20 is designed as 1.5F (F is thesystem focal length), wherein:

The specific design parameters of the short-range optical amplificationmodule are as shown in Table 3:

Surf Type Radius Thickness Glass Diameter Conic OBJ STANDARD Infinity−200 476.7014 0 STO STANDARD Infinity 9 9 0 2 STANDARD Infinity 4 H-QK3L30.04656 0 3 STANDARD −134.133 5.996206 33.5536 0 4 STANDARD Infinity 4H-QK3L 47.00138 0 5 STANDARD −99 −4 MIRROR 48.08787 0 6 EVENASPHInfinity −5.996206 48.07203 0 7 EVENASPH −134.133 −4 H-QK3L 47.88681 0 8STANDARD Infinity −0.2 PMMA 47.64044 0 9 STANDARD Infinity 0 MIRROR47.61382 0 10 STANDARD Infinity 0.2 PMMA 47.61382 0 11 STANDARD Infinity4 H-QK3L 47.58719 0 12 EVENASPH −134.133 5.996206 47.33418 0 13 EVENASPHInfinity 4 H-QK3L 44.22057 0 14 STANDARD −99 0.6 43.82507 0 15 STANDARDInfinity 0.4 BK7 41.91615 0 IMA STANDARD Infinity 41.9188 0

For the explanation of other relevant parameters in this embodiment,reference may be made to Table 1 of Embodiment 1, which will not beagain described one by one here.

Other corresponding parameters of the short-range optical amplificationmodule are as shown in Table 4:

Screen size C (inch) 2.3 Field angle V (°) 100 System focal length F(mm) 26.4 The effective focal length fs4 of the 1.88F reflection surfaceof the transflective surface Eyebox (mm) 9 Screen resolution 2500 * 2500Optical system thickness (mm) 15 Eye relief (mm) 9 F# aperture 2.9Optical outer diameter (mm) 48 System distortion D 33.4 First focallength f2 of the second lens  1.5F Focal length f1 of the first lens10.4F

By the relevant parameters as shown in Table 3, it is clear from Table 4that the focal length of the first lens 10 will be 10.4F (274.56 mm),the first focal length of the second lens 20 will be 1.5F (39.6 mm), andthe effective focal length of the reflection surface of thetransflective surface of the second lens 20 will be 1.88F (49.63 mm),and the thickness of the optical system will be 15 mm, thus it mayobtain a system focal length of 26.4 mm and a wide field angle of 100°,by designing the aperture set in front of the short-range opticalamplification module as 2.9, that is, designing the diameter D of thecorresponding diaphragm as 9.1 mm, a large eyebox of 9 mm may beobtained accordingly.

Furthermore, the screen size is designed as 2.3 inch, and the eye reliefis designed as 9 mm; in conjunction with the MTF diagram of FIG. 7, itmay obtain the abscissa (spatial frequency per millimeter) value with anaverage ordinate (modulation transfer function) higher than 0.18 in eachvisual field, thereby it may be obtained that the resolving power of theshort-range optical amplification module may support a resolution of2500*2500; moreover, the distortion factor in FIG. 8 is controlledwithin a range of (−33.4%, 0), and the field curvature in FIG. 9 iscontrolled within a range of (−1 mm, 1 mm).

Embodiment 3

As shown in FIG. 10, in the short-range optical amplification module,the focal length of the first lens 10 is designed as 6.7F, and the firstfocal length f2 of the second lens 20 is designed as 1.6F (F is thesystem focal length), wherein:

The specific design parameters of the short-range optical amplificationmodule are as shown in Table 5:

Surf Type Radius Thickness Glass Diameter Conic OBJ STANDARD InfinityInfinity 0 0 1 PARAXIAL — 0 8 — STO STANDARD Infinity 9 8 0 3 STANDARDInfinity 0.3 BK7 29.41556 0 4 STANDARD Infinity 0 29.76683 0 5 STANDARDInfinity 3.5 PMMA 29.76683 0 6 EVENASPH −54.86904 3.419999 31.52462−29.9693 7 EVENASPH −276.5358 3 PMMA 39.6142 0 8 STANDARD −63.86492 −3MIRROR 40.10655 0 9 EVENASPH −276.5358 −3.419999 39.94254 0 10 EVENASPH−54.86904 −3.5 PMMA 37.59622 −29.9693 11 STANDARD Infinity 0 37.25802 012 STANDARD Infinity −0.3 BK7 37.25802 0 13 STANDARD Infinity 0.3 MIRROR37.13014 0 14 STANDARD Infinity 0 37.00227 0 15 STANDARD Infinity 3.5PMMA 37.00227 0 16 EVENASPH −54.86904 3.419999 36.61711 −29.9693 17EVENASPH −276.5358 3 PMMA 31.11965 0 18 STANDARD −63.86492 0.5 30.2068 019 STANDARD Infinity 0.4 BK7 27.05452 0 IMA STANDARD Infinity 26.73411 0

In Table 5, the second row represents PARAXIAL design; the fourth rowrepresents the parameters related with the membrane consisting of areflective polarizing plate and a first phase delay plate in the opticalmodule; the sixth row and the seventh row represent the parametersrelated with the first lens 10, wherein, the second optical surface E2of the first lens 10 is EVENASPH aspheric surface; the eighth row andthe ninth row represent the parameters related with the first lens 20,wherein the third optical surface E3 of the second lens 20 is EVENASPHaspheric surface. For the explanation of other relevant parameters inthis embodiment, reference may be made to Embodiment 1, which will notbe again described again.

The refined design parameters of the optical surfaces in the short-rangeoptical amplification module are as shown in Table 6:

Surface OBJ: STANDARD Surface 1: PARAXIAL Focal length: 2000   OPD Mode:1 Surface STO: STANDARD Surface 3: STANDARD Surface 4: STANDARD Surface5: STANDARD Surface 6: EVENASPH Coeff on r 2: 0 Coeff on r 4:−1.7328621e−005 Coeff on r 6:  6.9557989e−008 Coeff on r 8:−1.5026388e−010 Coeff on r 10:  1.445203e−013 Coeff on r 12: 0 Coeff onr 14: 0 Coeff on r 16: 0 Surface 7: STANDARD Surface 8: STANDARD Surface9: EVENASPH Coeff on r 2: 0 Coeff on r 4: 0 Coeff on r 6: 0 Coeff on r8: 0 Coeff on r 10: 0 Coeff on r 12: 0 Coeff on r 14: 0 Coeff on r 16: 0Surface 10: EVENASPH Coeff on r 2: 0 Coeff on r 4: −1.7328621e−005 Coeffon r 6:  6.9557989e−008 Coeff on r 8: −1.5026388e−010 Coeff on r 10: 1.445203e−013 Coeff on r 12: 0 Coeff on r 14: 0 Coeff on r 16: 0Surface 11: STANDARD Surface 12: STANDARD Surface 13: STANDARD Surface14: STANDARD Surface 15: STANDARD Surface 16: EVENASPH Coeff on r 2: 0Coeff on r 4: −1.7328621e−005 Coeff on r 6:  6.9557989e−008 Coeff on r8: −1.5026388e−010 Coeff on r 10:  1.445203e−013 Coeff on r 12: 0 Coeffon r 14: 0 Coeff on r 16: 0 Surface 17: EVENASPH Coeff on r 2: 0 Coeffon r 4: 0 Coeff on r 6: 0 Coeff on r 8: 0 Coeff on r 10: 0 Coeff on r12: 0 Coeff on r 14: 0 Coeff on r 16: 0 Surface 18: STANDARD Surface 19:STANDARD Surface IMA: STANDARD

In Table 6, the aspheric surface formula is generally expressed asfollows:

$\begin{matrix}{x = {\frac{{cr}^{2}}{1 + \sqrt{1 - {{Kc}^{2}r^{2}}}} + {dr}^{4} + {er}^{6} + {fr}^{8} + {gr}^{10} + {hr}^{12} + {ir}^{14} + {jr}^{16}}} & (6)\end{matrix}$

Wherein: r is the distance from a point on the lens to the optical axis,c is curvature at the vertex of a curved surface, K is the conicconstant, and d, e, f, g, h, i, j are polynomial coefficients.

By substituting the values of the corresponding coefficients into xformula (6) respectively, the aspheric surface equation of each surfacewill be obtained.

Other corresponding parameters of the short-range optical amplificationmodule are as shown in Table 7:

Screen size C (inch) 1.49 Field angle V (°) 100 System focal length F(mm) 16.48 The effective focal length fs4 of the 1.9F reflection surfaceof the transflective surface Eyebox (mm) 8 Screen resolution 2600 * 2600Optical system thickness (mm) 11.1 Eye relief (mm) 9 F# aperture 2.1Optical outer diameter (mm) 40 System distortion D 32.8 First focallength f2 of the second lens 1.6F Focal length f1 of the first lens 6.7F

By setting the relevant parameters as shown in Tables 5 and 6, it isclear from Table 7 that the focal length of the first lens 10 will be6.7F (110.42 mm), the first focal length of the second lens 20 will be1.6F (26.368 mm), and the effective focal length of the reflectionsurface of the transflective surface of the second lens 20 will be 1.9F(94.297 mm), and the thickness of the optical system will be 11.1 mm,thus it may obtain a system focal length of 16.48 mm and a wide fieldangle of 100°, by designing the aperture set in front of the short-rangeoptical amplification module as 2.1, that is, designing the diameter Dof the corresponding diaphragm as 8 mm, a large eyebox of 8 mm may beobtained accordingly.

Furthermore, the screen size is designed as 1.49 inch, and the eyerelief is designed as 9 mm; in conjunction with the MTF diagram of FIG.11, it may obtain the abscissa (spatial frequency per millimeter) valuewith an average ordinate (modulation transfer function) higher than 0.18in each visual field, thereby it may be obtained that the resolvingpower of the short-range optical amplification module may support a highresolution of 2600*2600; moreover, it may be seen from FIG. 12 that theoptical imaging distortion factor in this embodiment may be controlledwithin a range of (−32.8%, 0%), and the field curvature in FIG. 13 maybe controlled within a range of (−0.5 mm, 0.5 mm).

Embodiment 4

As shown in FIG. 14, in the short-range optical amplification module,the focal length of the first lens 10 is designed as 8.2F, and the firstfocal length f2 of the second lens 20 is designed as 1.6F (F is thesystem focal length), wherein:

The specific design parameters of the short-range optical amplificationmodule are as shown in Table 8:

Surf Type Radius Thickness Glass Diameter Conic OBJ STANDARD Infinity−200 476.7014 0 STO STANDARD Infinity 9 9 0 2 STANDARD Infinity 4 H-QK3L30.04656 0 3 STANDARD −118.5728 7.181132 33.4005 0 4 STANDARD Infinity 4H-QK3L 49.01052 0 5 STANDARD −118.5728 −4 MIRROR 50.35067 0 6 EVENASPHInfinity −7.181132 50.47811 0 7 EVENASPH −118.5728 −4 H-QK3L 51.94988 08 STANDARD Infinity −0.2 PMMA 51.89456 0 9 STANDARD Infinity 0 MIRROR51.88471 0 10 STANDARD Infinity 0.2 PMMA 51.88471 0 11 STANDARD Infinity4 H-QK3L 51.87486 0 12 EVENASPH −118.5728 7.181132 51.81882 0 13EVENASPH Infinity 4 H-QK3L 48.8141 0 14 STANDARD −118.5728 0.6 48.515620 15 STANDARD Infinity 0.4 BK7 46.9492 0 IMA STANDARD Infinity 46.959520

For the explanation of the relevant parameters in Table 8 of thisembodiment, reference may be made to Embodiment 1 to Embodiment 3, whichwill not be again described one by one here.

Other corresponding parameters of the short-range optical amplificationmodule are as shown in Table 9:

Screen size C (inch) 2.6 Field angle V (°) 100 System focal length F(mm) 29.5 The effective focal length fs4 of the   2F reflection surfaceof the transflective surface Eyebox (mm) 9 Screen resolution 4000 * 4000Optical system thickness (mm) 16.2 Eye relief (mm) 9 F# aperture 3.2Optical outer diameter (mm) 52 System distortion D 33 First focal lengthf2 of the second lens 1.6F Focal length f1 of the first lens 8.2F

By setting the relevant parameters as shown in Tables 8, it is clearfrom Table 9 that the focal length of the first lens 10 will be 8.5F(241.9 mm), and the first focal length of the second lens 20 will be1.6F (47.2 mm), and the effective focal length of the reflection surfaceof the transflective surface of the second lens 20 will be 2F (59 mm),and the thickness of the optical system will be 16.5 mm, thus it mayobtain a system focal length of 29.5 mm mm and a wide field angle of100°; by designing the aperture set in front of the short-range opticalamplification module as 3.2, that is, designing the diameter D of thecorresponding diaphragm as 9.2 mm, a large eyebox of 9 mm may beobtained accordingly.

Furthermore, the screen size is designed as 2.6 inch, and the eye reliefis designed as 9 mm; in conjunction with the MTF diagram of FIG. 15, itmay obtain the abscissa (spatial frequency per millimeter) value with anaverage ordinate (modulation transfer function) higher than 0.18 in eachvisual field, thereby it may be obtained that the resolving power of theshort-range optical amplification module may support a resolution of4000*4000; moreover, it may be seen from FIG. 16 that the distortionfactor may be controlled within a range of (−33%, 0), and the fieldcurvature in FIG. 17 may be controlled within a range of (−0.5 mm, 0.5mm).

Embodiment 5

As shown in FIG. 18, in the short-range optical amplification module,the focal length of the first lens 10 is designed as 3.8F, and the firstfocal length f2 of the second lens 20 is designed as 2F (F is the systemfocal length), wherein:

The specific design parameters of the short-range optical amplificationmodule are as shown in Table 10:

Surf Type Radius Thickness Glass Diameter Conic OBJ STANDARD InfinityThickness 0 0 1 PARAXIAL — 0 7.8 — STO STANDARD Infinity 9 7.8 0 3STANDARD Infinity 0.3 BK7 29.21646 0 4 STANDARD Infinity 0 29.56774 0 5STANDARD Infinity 7 PMMA 29.56774 0 6 EVENASPH −34.11663 2.63124733.25403 −12.66719 7 EVENASPH −69 2 BK7 38.47584 0 8 STANDARD −72 −2MIRROR 40.43752 0 9 EVENASPH −69 −2.631247 40.10675 0 10 EVENASPH−34.11663 −7 PMMA 40.47701 −12.66719 11 STANDARD Infinity 0 40.1165 0 12STANDARD Infinity −0.3 BK7 40.1165 0 13 STANDARD Infinity 0.3 MIRROR40.04031 0 14 STANDARD Infinity 0 39.96411 0 15 STANDARD Infinity 7 PMMA39.96411 0 16 EVENASPH −34.11663 2.631247 39.54659 −12.66719 17 EVENASPH−69 2 BK7 33.05867 0 18 STANDARD −72 0.5 32.08565 0 19 STANDARD Infinity0.4 BK7 29.67339 0 IMA STANDARD Infinity 29.41675 0

For the explanation of the relevant parameters in Table 10 of thisembodiment, reference may be made to Embodiment 1 to Embodiment 3, whichwill not be again described one by one here.

The refined design parameters of the optical surfaces in the short-rangeoptical amplification module are as shown in Table 11:

Surface OBJ: STANDARD Surface 1: PARAXIAL Focal length: 2000   OPD Mode:1 Surface STO: STANDARD Surface 3: STANDARD Surface 4: STANDARD Surface5: STANDARD Surface 6: EVENASPH Coeff on r 2: 0 Coeff on r 4:−3.2267582e−005 Coeff on r 6:  9.7858135e−008 Coeff on r 8:−1.6661362e−010 Coeff on r 10:  1.2640734e−013 Coeff on r 12: 0 Coeff onr 14: 0 Coeff on r 16: 0 Surface 7: STANDARD Surface 8: STANDARD Surface9: EVENASPH Coeff on r 2: 0 Coeff on r 4: 0 Coeff on r 6: 0 Coeff on r8: 0 Coeff on r 10: 0 Coeff on r 12: 0 Coeff on r 14: 0 Coeff on r 16: 0Surface 10: EVENASPH Coeff on r 2: 0 Coeff on r 4: −3.2267582e−005 Coeffon r 6:  9.7858135e−008 Coeff on r 8: −1.6661362e−010 Coeff on r 10: 1.2640734e−013 Coeff on r 12: 0 Coeff on r 14: 0 Coeff on r 16: 0Surface 11: STANDARD Surface 12: STANDARD Surface 13: STANDARD Surface14: STANDARD Surface 15: STANDARD Surface 16: EVENASPH Coeff on r 2: 0Coeff on r 4: −3.2267582e−005 Coeff on r 6:  9.7858135e−008 Coeff on r8: −1.6661362e−010 Coeff on r 10:  1.2640734e−013 Coeff on r 12: 0 Coeffon r 14: 0 Coeff on r 16: 0 Surface 17: EVENASPH Coeff on r 2: 0 Coeffon r 4: 0 Coeff on r 6: 0 Coeff on r 8: 0 Coeff on r 10: 0 Coeff on r12: 0 Coeff on r 14: 0 Coeff on r 16: 0 Surface 18: STANDARD Surface 19:STANDARD Surface IMA: STANDARD

Other corresponding parameters of the short-range optical amplificationmodule are as shown in Table 12:

Screen size C (inch) 1.66 Field angle V (°) 100 System focal length F(mm) 18 The effective focal length fs4 of the 1.9F reflection surface ofthe transflective surface Eyebox (mm) 8 Screen resolution 2000 * 2000Optical system thickness (mm) 12.8 Eye relief (mm) 9 F# aperture 2.3Optical outer diameter (mm) 40 System distortion D 32.5 First focallength f2 of the second   2F lens Focal length f1 of the first lens 3.8F

By setting the relevant parameters as shown in Tables 10 and 11, it isclear from Table 12 that the focal length of the first lens 10 will be3.8F (68.4 mm), and the first focal length of the second lens 20 will be2F (36 mm), and the effective focal length of the reflection surface ofthe transflective surface of the second lens 20 will be 1.9F (34.2 mm),and the thickness of the optical system will be 12.8 mm, thus it mayobtain a system focal length of 18 mm and a wide field angle of 100°; bydesigning the aperture set in front of the short-range opticalamplification module as 2.3, that is, designing the diameter D of thecorresponding diaphragm as 8 mm, a large eyebox of 8 mm may be obtainedaccordingly.

Furthermore, the screen size is designed as 1.66 inch, and the eyerelief is designed as 9 mm; in conjunction with the MTF diagram of FIG.19, it may obtain the abscissa (spatial frequency per millimeter) valuewith an average ordinate (modulation transfer function) higher than 0.18in each visual field, thereby it may be obtained that the resolvingpower of the short-range optical amplification module may support aresolution of 2000*2000, and the distortion factor in FIG. 20 iscontrolled within a range of (−32.5%, 0), and the field curvature inFIG. 21 is controlled within a range of (−0.5 mm, 0.5 mm).

Moreover, the effective focal length of the reflection surface of thetransflective surface is not limited to being designed as 1.9F, and itmay also be designed as 5F; the thickness of the optical system and theeye relief are not limited to being designed respectively as 12.8 mm and9 mm, and they may also be designed as 28 mm and 10 mm respectively.

Based on the short-range optical amplification module according to thisembodiment, there is further provided a pair of spectacles whichincludes the short-range optical amplification module in the aboveembodiments. The spectacles further include a screen 30 which is setcoaxially or noncoaxially with the short-range optical amplificationmodule. The screen 30 in FIG. 2, FIG. 6, FIG. 10, FIG. 14 and FIG. 18 isset coaxially with the short-range optical amplification module;however, in use, the screen 30 may be set coaxially or noncoaxially withthe short-range optical amplification module according to specificapplication requirements.

Based on the short-range optical amplification module according to thisembodiment, there is further provided a helmet which includes theshort-range optical amplification module in the above embodiments. Thehelmet further includes a screen 30 which is set coaxially ornoncoaxially with the short-range optical amplification module. Thescreen 30 in FIG. 2, FIG. 6, FIG. 10 and FIG. 14 is set coaxially withthe short-range optical amplification module here for the convenience ofexpression; however, in use, the screen 30 may be set coaxially ornoncoaxially with the short-range optical amplification module accordingto specific application requirements.

Based on the spectacles and the helmet described herein, there isfurther provided a VR system which includes the spectacles or the helmetin the above embodiments and is used in an intelligent Virtual Reality(VR) wearable device. The said VR system includes a pair of spectaclesor a helmet containing the short-range optical amplification module areor is employed, so that the VR system will have a wide field angle, alarge eyebox, high-quality imaging effect and a compact ultrathinstructure, etc., and hence it can provide a good user experience.Specifically, reference may be made to the embodiments of theshort-range optical amplification module.

It should be noted that, the ordinal adjectives such as “first” and“second” employed herein are only used for distinguishing one entity oroperation from another entity or operation, rather than requiring orimplying that these entities or operations must have certain relationsor be in a given sequence. Moreover, the terms “include”, “comprise” orany variations thereof intend to encompass nonexclusive inclusion, sothat a process, a method, an object or a device that are said to includea series of essential factors not only include such essential factors,but also include other essential factors that are not listedspecifically or essential factors inherent in such a process, method,object or device. In the case of no other limitation, an essentialfactor defined by a sentence “includes a . . . ” does not exclude thatadditional similar essential factors may exist in the process, method,object or device that includes said essential factor.

The above description only shows some specific embodiments of thepresent invention for one skilled in the art to be able to understand orimplement the invention. Various modifications to these embodiments areapparent to those skilled in the art. The general principles definedherein may be implemented in other embodiments without departing fromthe spirit or scope of the present invention. Therefore, the presentinvention will not be limited to the embodiments described herein;instead, the invention conforms to the widest scope that is consistentwith the principles and novel features disclosed herein.

What is claimed is:
 1. A short-range optical amplification module,comprising: a reflective polarizing plate, a first phase delay plate, asecond lens and a second phase delay plate that are arrangedsequentially, wherein: a first lens is further set on either side of anyone of the reflective polarizing plate, the first phase delay plate, thesecond lens and the second phase delay plate; in the second lens, anoptical surface adjacent to the second phase delay plate is atransflective optical surface; and a first focal length f2 of the secondlens meets the following condition: 1F≤f2≤2F, wherein F is a systemfocal length of the short-range optical amplification module.
 2. Theshort-range optical amplification module according to claim 1, whereinan effective focal length fs4 of a reflection surface of thetransflective optical surface meets the following condition:1.5F≤fs4≤5F.
 3. The short-range optical amplification module accordingto claim 2, wherein the effective focal length fs4 of the reflectionsurface of the transflective optical surface meets the followingcondition: 1F≤fs4≤2F.
 4. The short-range optical amplification moduleaccording to claim 1, wherein the first focal length f2 of the secondlens meets the following condition: 1.5F≤f2≤2F.
 5. The short-rangeoptical amplification module according to claim 4, wherein the firstfocal length f2 of the second lens is 1.6F.
 6. The short-range opticalamplification module according to claim 1, wherein in the second lens, afocal length fs3 of an optical surface adjacent to the first lens meetsthe following condition: |fs3|≥2F.
 7. The short-range opticalamplification module according to claim 1, wherein a focal length f1 ofthe first lens meets the following condition: |f1|≥3F.
 8. Theshort-range optical amplification module according to claim 1, wherein athickness of the short-range optical amplification module is 11 mm˜28mm.
 9. The short-range optical amplification module according to claim1, wherein an eye relief of the short-range optical amplification moduleis 5˜10 mm.
 10. The short-range optical amplification module accordingto claim 1, wherein an aperture D, through which light that takes partin imaging via the second lens and the first lens passes, meets thefollowing condition: 0.28≤F≤D≤0.45F.
 11. A short-range opticalamplification spectacles, comprising: the short-range opticalamplification module according to claim 1 and a display screen, whereinthe display screen is set coaxially or noncoaxially with the short-rangeoptical amplification module.
 12. A short-range optical amplificationVirtual Reality (VR) system, comprising: the spectacles according toclaim
 11. 13. A short-range optical amplification helmet, comprising:the short-range optical amplification module according to claim 1 and adisplay screen, wherein the display screen is set coaxially ornoncoaxially with the short-range optical amplification module.
 14. Ashort-range optical amplification Virtual Reality (VR) system,comprising: the helmet according to claim 13.